Add a feature based dummy implementation

engine/src/audio_engine/jack_ab.rs

@@ -1,16 +1,21 @@
 use crate::audio_engine::AudioBackend;
 
 pub(crate) struct JackAudioBackend {
-    pub(crate) name: String,
+    pub(crate) feature_jack: bool,
     pub(crate) running: bool,
 }
 
 impl JackAudioBackend {
-    pub(crate) fn new(name: String, running: bool) -> Self {
-        Self { name, running }
+    pub(crate) fn new() -> Self {
+
+        let feature_jack = cfg!(feature = "jack");
+        // TODO: It should be retrieved from the system
+        let running = true;
+        Self { feature_jack, running }
     }
 }
 
+#[cfg(feature = "jack")]
 impl AudioBackend for JackAudioBackend {
     fn start_client(&self) {
         todo!()
@@ -24,3 +29,18 @@ impl AudioBackend for JackAudioBackend {
         todo!()
     }
 }
+
+#[cfg(not(feature = "jack"))]
+impl AudioBackend for JackAudioBackend {
+    fn start_client(&self) {
+        unimplemented!()
+    }
+
+    fn init_client(&self) {
+        unimplemented!()
+    }
+
+    fn discover(&self) {
+        unimplemented!()
+    }
+}

engine/src/audio_engine/mod.rs

@@ -1,4 +1,3 @@
-#[cfg(feature = "jack")]
 pub(crate) mod jack_ab;
 
 pub(crate) trait AudioBackend {

engine/src/control_pane/grpc/mod.rs

@@ -7,9 +7,7 @@ use tonic::{Response, transport::Server};
 use tonic_reflection::server;
 
 
-use crate::control_pane::ControlPane;
-#[cfg(feature = "jack") ]
-use crate::audio_engine::jack_ab::JackAudioBackend;
+use crate::{audio_engine::jack_ab::JackAudioBackend, control_pane::ControlPane};
 
 pub(crate) struct Grpc {
     pub(crate) port: i32,
@@ -65,8 +63,8 @@ impl AudioBackend for TermixAudioBackend {
     ) -> Result<Response<BackendList>, tonic::Status> {
         info!("discovering available backends");
         let mut response = BackendList::default();
-        if cfg!(feature = "jack") {
-            let jack = JackAudioBackend{ name: "jack".to_string(), running: todo!() };
+        let jack = JackAudioBackend::new();
+        if jack.feature_jack {
           response.backends.push(Backend {
             name: "jack".to_string(),
           });